Apparatus for the relieving of pressure in melting-pots, &amp;c.



H; PETERSEN.

APPARATUS FOR THE RELIEVING 0F PRESSURE IN MELTING POTS. 61c.

APPLICATION FILED JULY l2. I915.

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HANS PETERSEN, 0F DAVENPORT, IOWA.

Specification of Letters Patent.

Patented Dec. 5, 19116.

Application filed July 12, 1915. Serial No. 39,360.

To all whom it may concern:

Be it known that I, HANS PETERSEN, a citizen of the United States, residing at Davenport, in the county of Scott and State of Iowa, have invented certain new and useful Improvements in Apparatus for the Relieving of Pressure in Melting-Pots, etc., of which the following is a specification.

This invention relates to an improved apparatus for the relieving of pressure in melting pots, crucibles, and the like, in which a mass of metal has once been melted, allowed to cool in the melting pot and is again melted for casting or pouring purposes. WVhen a charge of metal has been reduced in a melting pot and allowed to cool therein, in reheating the charge of metal that portion of the charge at the bottom of the melting pot becomes heated first, and begins to expand before the upper portion of the charge is sufiiciently warm to permit of this expansion. As a consequence extremely high pressure is produced in the bottom of the crucible suflicient at times to disrupt or rend the crucible, and at other times to force very fine threads of molten metal through the pores in the walls of the melting pot or crucible and these fine threads of metal passing down through the bottom of the crucible on to the burner, tend to obstruct or clog the same.

The present invention provides an improved apparatus whereby, in the reheating of the charge, the pressure in the melting pot, crucible or the like, is relieved andthe difficulties and objectionable conditions referred to are entirely avoided. I

In accordance with the invention, when the pouring or casting operation is suspended and the charge left to cool in the melting pot, a portion of the mass of metal is displaced by inserting into the mass centrally of and from the top thereof a displacing element in the form of a plug or bar, and said displacing element is permitted to set or freeze in the charge. The displacing element is inserted into the mass of metal to a depth to extend to the bottom of the mass. When it is desired to again re duce the metal in the crucible or melting pot to a molten state the displacing element is first removed leaving an opening or channel extending centrally through the mass from the top to the bottom thereof. In the operation of reheating the charge, the pressure at the bottom of the crucible or melting pot is relieved, the newly molten metal at the bottom working its way upward through the aforesaid opening or channel as the melting proceeds, and in this way a more or less uniform melting or liquefaction of the metal without undue pressure in any particular portion of the crucible is secured.

In the drawing 1 have illustrated an apparatus for carrying the method into effect.

Figure l is a vertical section of a melting pot of well known construction; Fig. 2 is a similar view showing the pump plunger removed and the displacing element inserted into the charge in the crucible; and Fig. 3 is a like view with the displacing member removed and showing the channel or opening extending centrally through the chilled mass.

Referring to the drawings in detail 1 designates a melting pot or crucible of well known construction provided with the usual spout 2, a centrally arranged pump cylinder 3 open at both ends, and a pump plunger or piston 4 adapted to reciprocate in the pump cylinder and to be removed therefrom.

5 designates a burner of any suitable type for the melting pot.

A displacing element is provided in the form of a metal plug or bar 6 circular in cross section and tapering longitudinally, provided at its upper end with a portion 7 constituting a grip or handle, said grip or handle portion 7 having an opening 8 extending therethrough in which a withdrawing bar or hook can be inserted. The bar at its lower end is preferably pointed as shown to facilitate its insertion into the mass of metal. The bar is also preferably constructed of cold rolled steel and provided with a smoothly polished exterior surface, this construction facilitating the withdrawal of the displacing member from the cold mass of metal.

Then the pouring or casting operation is to be suspended and a charge of molten metal is left to cool in the crucible, the pump plunger or piston is removed and the tapered bar 6 is inserted centrally into the mass through the pump cylinder, the size of the bar 6 being such that the same can readily pass through the pump cylinder and so that the upper portion of the bar when the bar has been inserted in position will engage the upper portion of the wall of the pump cylinder, the pump cylinder 'constitubing a guide for the displacement member,

during the insertion of the same, and also as a support to maintain the same in position.

What I claim is: a

1. The combination with a melting pot provided with a pump cylinder open at its top and bottom of a device consisting of a bar of steel, said bar having a grip at one end and being adapted to be inserted into a molten charge of metal in the melting pot and permitted to set or freeze in the charge and to be withdrawn from the charge after the same has cooled to provide an opening in the chilled mass, said bar being of a size in cross section to permit the insertion thereof through the pump cylinder and to rest against the pump cylinder when in place in the melting pot, the pump cylinder serving as a guide and supporting means for the bar while in the melting pot.

2. The combination with a melting pot provided with a pump cylinder open at its top and bottom and disposed centrally of the melting pot, of a deviceconsisting of a smooth bar of steel adapted to be inserted into a molten charge of metal in the melting pot and permitted to set or freeze in the charge and to be withdrawn from the charge after the same has cooled to provide an opening in the chilled mass extending centrally fromthe top to near the bottom thereof, the bar being of a size in cross section to permit the insertion of the same through the pump cylinder and to be engaged by a portion of the pump cylinder when in place in the melting pot, the pump cylinder serving as a guide and support for said bar.

3. The'combination with a melting pot provided with a pump cylinder open at its Copies of this patent may be obtained for top and bottom, of a plug adapted to be inserted into a molten charge of metal in the melting pot, and permitted to set or freeze in the charge, said plug being of a size in cross section to permit the insertion thereof through the pump cylinder and to rest against the pump cylinder when in place in the melting pot, the pump cylinder serving as a guide and supporting means for the plug while in the melting pot.

4. The combination with a melting pot provided with a pump cylinder open at its top and bottom, of a plug adapted to be inserted into a molten charge of metal in the melting pot and permitted to set or freeze in the charge, said plug being of a size in cross section to permit the insertion thereof through the pump cylinder.

5. The combination with a melting pot provided with a pump cylinder open at its top and bottom, of a plug adapted to be inserted into a molten charge of metal in the melting pot and permitted to set or freeze in the charge and to be withdrawn from the charge after the mass has cooled to provide an opening in the chilled mass,

five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

